By Lina carolina 
A groundbreaking new study, leveraging a pioneering technique developed by researchers at University College London (UCL) and the Francis Crick Institute, has unveiled a profound connection between the abundance of immune cells in cancer patients’ blood and their survival rates. This innovative approach, detailed in the prestigious journal Nature Genetics, enables scientists to quantify T cells and B cells—critical components of the immune system—directly from whole genome sequencing (WGS) data, a feat previously unattainable. The findings suggest that the immune system’s status in the bloodstream, not just within the tumor itself, holds significant prognostic power and could revolutionize how cancer is diagnosed and treated.
The Power of ImmuneLENS: Unlocking Blood’s Immune Secrets
The newly developed tool, christened Immune Lymphocyte Estimation from Nucleotide Sequencing (ImmuneLENS), represents a significant leap forward in our ability to understand the complex interplay between the immune system and cancer. Whole genome sequencing, a comprehensive analysis of an individual’s entire DNA, typically used to identify genetic mutations and understand disease, can now also serve as a powerful diagnostic window into the patient’s immune landscape. ImmuneLENS mines this rich genetic data, extracting information about the proportion of T and B cells circulating in the blood. This breakthrough allows for a more holistic assessment of a patient’s immune health, moving beyond localized tumor analysis to a systemic view.
The research team applied ImmuneLENS to an extensive dataset comprising over 90,000 whole genome sequencing samples from the landmark 100,000 Genomes Project. This ambitious initiative, spearheaded by Genomics England and NHS England, has meticulously cataloged the genetic blueprints of a vast cohort, including both healthy individuals and those battling cancer. By analyzing this immense repository, researchers were able to establish robust comparisons and identify key trends.
A Stronger Immune Presence, A Better Prognosis
The study’s findings revealed a striking disparity: cancer patients, on average, exhibited a lower proportion of T cells in their blood compared to their healthy counterparts. More importantly, this T cell proportion emerged as a potent predictor of cancer outcomes. Individuals with a higher percentage of circulating T cells demonstrated a remarkable 47% reduction in deaths over a five-year period following surgery. This association remained statistically significant even after accounting for critical factors such as age, cancer stage, and across all cancer types analyzed. This suggests that the systemic immune response, as reflected in blood counts, plays a crucial role in a patient’s ability to fight the disease and recover.
Professor Nicholas McGranahan, senior author of the study from the UCL Cancer Institute, emphasized the transformative potential of this new methodology. "Most immune system analysis until now has focused on the tumour itself, so the results we’re seeing using this new technique—which examines the number of immune cells in a person’s blood—are of considerable interest," he stated. "What’s going on with immune cells in the blood seems to have a huge impact on cancer survival and may be able to predict how long a cancer patient will survive better than the number of T cells in the tumour alone."
Professor McGranahan further elaborated on the paradigm shift ImmuneLENS offers. "There have been hints in previous research that this might be important, but being able to analyse immune system information at this scale is game-changing," he noted. "The ability to compare immune cell changes in the blood and to what’s happening in the tumour environment opens up new avenues for cancer research, as well as healthcare research more widely." He highlighted the direct clinical implications: "In terms of patient diagnosis and treatment, knowing whether a patient has relatively high or low numbers of immune cells in the blood, and how this corresponds to their prognosis, could help clinicians to decide on the best course of treatment for the individual."
The Immune System’s Battle Against Cancer: A Complex Dynamic
Cancer, at its core, is a disease driven by genetic mutations within the body’s cells. While the immune system is equipped to detect and eliminate cells with dangerous mutations, cancer cells often develop sophisticated mechanisms to evade this immune surveillance and actively disrupt the immune response. Understanding these evasive tactics and the immune system’s counter-strategies is paramount to developing effective treatments.
Assessing changes not only in the immediate vicinity of the tumor (the local immune environment) but also in the broader systemic immune system is therefore crucial for comprehending cancer’s progression and predicting a patient’s response to therapy. Large-scale genomic initiatives, such as the 100,000 Genomes Project, have provided unprecedented access to comprehensive genetic data from a diverse patient population. However, until the advent of ImmuneLENS, a detailed understanding of the precise immune cell composition within both the tumor and the wider immune system has remained elusive.
ImmuneLENS builds upon earlier work, including a 2021 method that allowed for the calculation of T cell proportions in whole exome sequencing data. This latest advancement significantly broadens the scope, enabling the analysis of T and B cells from the more comprehensive whole genome sequencing.
Age, Sex, and Early Detection: Unforeseen Clues
Beyond the direct correlation with survival, the study unearthed intriguing age-related trends and potential early detection indicators. It is well-established that the proportion of immune cells in the blood naturally declines with age in healthy individuals. However, the researchers found that this decline occurs earlier and more pronouncedly in individuals diagnosed with cancer.
Interestingly, this age-related immune cell reduction was observed to be more significant in male cancer patients compared to their female counterparts. The exact reasons for these observed sexual differences remain unclear and warrant further investigation to determine if they have an impact on overall cancer survival.
Perhaps one of the most compelling findings relates to individuals who appeared healthy at the time of their genetic sampling but later developed cancer. These individuals often exhibited below-average levels of B cells in their blood. This observation could signify undiagnosed early-stage cancer or pre-cancerous changes within the immune system that might serve as an early warning sign of disease, or even contribute to the development of cancer itself. This could pave the way for future cancer early detection strategies and provide clinicians with valuable insights into a patient’s likely response to treatment.
Dr. Robert Bentham, the study’s first author from the UCL Cancer Institute, likened the breakthrough to a more efficient method of discovery. "Lots of approaches that measure immune cells from genetic data are like looking for a needle in a haystack," he explained. "Our approach in this study instead looks at the haystack itself and asks how the presence of immune cells changes its overall shape. It’s a different, more efficient way of finding the needle."
Dr. Bentham highlighted the future potential: "One of the things this will allow us to do is to build significant immune datasets using data we already have from the many large-scale WGS cohorts but haven’t been able to interrogate until now. It will allow researchers to explore what’s happening in the immune system during health and disease, not just in cancer but potentially in many areas of medicine."
Distinguishing B Cell Subtypes: A New Frontier
The ImmuneLENS methodology also offers the ability to easily differentiate between various types of B cells. As B cells mature, they specialize to produce specific antibodies—proteins crucial for neutralizing harmful substances like viruses, bacteria, and mutated cells. The researchers ingeniously utilized this specialization process to identify and classify B cells.
When applied to WGS data, this detailed B cell analysis revealed a significant finding: B cells producing IgM/D antibodies—the type generated upon the body’s initial encounter with a foreign antigen—were the only B cell subtype associated with improved survival outcomes in cancer patients. This suggests a potentially pivotal role for these specific B cells in anti-tumor immunity. Their presence could serve as a novel biological marker for cancer diagnosis, marking them as a promising target for future research and therapeutic development.
Towards Clinical Integration: No Extra Cost, Significant Gain
A key next step for the research team is the clinical integration of these newly identified biological markers. They anticipate that these markers could be incorporated into existing diagnostic tests for cancer patients at no additional cost. Professor McGranahan and his team have already secured a Cancer Research UK (CRUK) funded Biomarker Project Award to facilitate this translation into clinical practice.
This development is particularly significant for predicting patient responses to immunotherapy. While the proportion of T cells within a tumor is a recognized biomarker, it cannot be currently measured using standard genomic tests. ImmuneLENS offers a way to bridge this gap, providing crucial information that could guide immunotherapy decisions.
Dr. Nisharnthi Duggan, Research Information Manager at Cancer Research UK, expressed enthusiasm for the ongoing work. "Cancer Research UK is pleased to support this ongoing work investigating whether measuring immune cell levels in our blood can help predict cancer survival," she stated. "We’re living in a golden age of research where we can use patient data in sophisticated ways to help us better understand cancer and how to beat it." She added, "Further research is needed, but this could one day become a tool to help doctors personalize treatment for people with cancer."
This groundbreaking research is an integral part of the Cancer Research UK-funded TRACERx project, a major initiative dedicated to understanding tumor evolution and treatment resistance. The study’s reliance on the data and findings generated by the 100,000 Genomes Project, managed by Genomics England, underscores the immense value of large-scale, collaborative genomic initiatives in driving medical innovation.
The implications of ImmuneLENS extend far beyond cancer. By enabling the analysis of immune cell populations from existing genomic data, this technology opens doors to exploring the immune system’s role in a multitude of health and disease states, potentially transforming our understanding and treatment of conditions ranging from autoimmune disorders to infectious diseases. The ability to efficiently interrogate the immune landscape within vast existing datasets promises to accelerate scientific discovery across the medical spectrum.
